碳化硅体积分数对SiCp/Al-30Si复合材料组织与性能的影响

摘要

采用真空热压烧结法制备SiC颗粒体积分数分别为20%、25%和30%的SiCp/Al-30Si复合材料。利用扫描电镜对复合材料的微观组织进行表征，并检测其力学性能及物理性能，运用Turner、Kerner理论模型对材料的热膨胀系数进行计算，分析碳化硅体积分数对SiCp/Al-30Si复合材料组织及性能的影响。研究结果表明：随SiC含量的增加，复合材料的组织中会出现SiC颗粒的团聚，使材料的致密度及抗拉强度下降，在50~100℃之间的热膨胀系数降低，其平均值与Kerner模型计算值很接近。%SiCp/Al-30Si composites were fabricated by vacuum hot pressing plus sintering, with the SiC particle volume fraction being 20%, 25%, 30%respectively. The microstructures of the materials were analyzed by SEM, and the tensile strength and thermal physical properties were examined. Turner and Kerner theoretical models were employed to calculate the coefficients of the thermal expansion. The influence of the SiC particle volume fraction on the microstructures and performances of the SiCp/Al-30Si composite was analyzed. The results show that, with the increase of the volume fraction of the SiC particles in the composites, the SiC particles distribute more ununiformly, and the clustering degree of the SiC particles increases in the matrix, resulting in decreasing tensile strength and densification. The coefficient of thermal expansion decrease from 50 ℃ to 100 ℃, in agreement with the Kerner theoretical model predictions.